Outboard motor for watercraft



April 7, 1954. v. N. DAVIES OUTBOARD MOTOR FOR WATERCRAFT 8 Sheebs-Sheet 1 Filed Dec. 11 1951,

y a w 7104:!

Attorney Ap 27, 1954- v. N. DAVIES 2,676,559

OUTBOARD MOTOR FOR WATERCRAFT Filed Dec. 11, 1951 8 Sheets-Sheet 2 Inventor W670i? IV. DAV/E6 Attorney y @211 my OUTBOARD MOTOR FOR WATERCRAFT Filed Dec. 11, 1951 8 Sheets-Sheet 3 Attorney April 27, 1954 V. N. DAVIES OUTBOARD MOTOR FOR WATERCRAFT Attorney April 27, 1954 v. N. DAVIES 2,676,559

OUTBOARD MOTOR FOR WATERCRAFT Filed Dec; 11, 1951 I 8 Sheets-Sheet 5 Inventor v/cm/a DAV/5 Attorney April 27, 1954 Filed Dec. 11 1951 V. N. DAVIES OUTBOARD MOTOR FOR WATERCRAFT .8 Sheets-Sheet 6 Inventor V/CmR N DAV/f5 By 0%; 775cm A ttor ney April 27, 1954 v, DAWES 2,676,559

OUTBOARD MOTOR FOR WATERCRAFT I Filed Dec. 11, 1951 8 Sheets-Sheet 7 Inventor VICTOR /V. DAV/f5 A Home y April 27, 1954 v N D s OUTBOARD MOTOR FOR WATERCRAFT 8 Sheets-Sheet 8 Filed Dec. 11 l95l In venfor V/CTUR IV. DA V/fS By 61% 7246! A Home y Patented Apr. 27, 1954 j UNITED STATES ATENT OFFICE 13 Claims.

This invention concerns an improved outboard motor unit for watercraft capable of being propelled by such a unit, e. g. dinghies,'skiifs, and like relatively small boats (all hereinafter included in the term boat) the outboard motor unit being of the kind comprising an internal combustion engine driving a remotely situated screw propeller through a driving shaft extending between the engine and the said propeller and enclosed in a housing having means for attaching the unit pendently to the stern or transom of the boat.

An object of this invention is to provide a generally improved outboard motor unit of the kind specified and in which the engine is thoroughly protected from its external surroundings and from water spray, rain, dirt and the like and from mechanical damage from external sources. A further object of the invention is to'provide a compact and highly serviceable outboard motor unit having a number of advantageous characteristics all of which will become apparent from the following description and claims.

According to the invention there is provided an outboard motor unit of the kind specified including a hollow rigid casing'comprising an upper and a lower part, the engine of the unit being carried in and fixed to the said lower casing part which is disposed over, and rigidly connected to, the upper end of the driving-shaft housing of the unit so that this housing depends from said lower casing part, whilst the said upper casing part constitutes a co'ver which, when closed, co-opcrates with the said lower casing part to enclose and protect-the engine. I The said engine is preferably a two-stroke reciprocating piston engine disposed on its side in the said lower casing part with the crank shaft of the engine aligned with the driving shaft in said driving-shaft housing.

Conveniently the said casing is in the form of a rectangular parallelepipedon, but it may be of other forms, e. g. of a streamlined form, and is divided horizontally or substantially horizontally, into two complementary parts which are hinged together along one edge, and have fastening means at the opposite edge thereof, resilient sealing means preferably being provided between the upper and lower parts of the casing so that when the upperrpart is closed down on to the lower part a water-tight joint is made between the two parts.

1 According to a still further feature of the invention the upper part ofthe said casing embodies afuel tank for the engine and is provided with a filling opening to nable fuel to be placedv in the tank, a flexible pipe being provided between,

the fuel tank and the engine carburetor for supplying fuel to the latter whilst also permitting the upper part of the casing to be moved withv respect to the lower part of the casing without interrupting the supply of fuel to the carburetor. Although the engine crank shaft could be coupled directly to the driving shaft of the unit it is preferred, in accordance with a further feature of this invention, to interpose a clutch assembly between the said crank and driving shafts of the unit, the said clutch assembly being located in a clutch housing disposed between the bottom of the said casing and the upper end of the said driving-shaft housing and rigidly associated with both of these parts. The said clutch assembly preferably comprises a drum and expanding friction shoes as will hereinafter be more fully explained.

According to a further feature of the invention,

the said driving-shaft housing also constitutes the exhaust pipe for the engine, the said housing having an exhaust opening at its lower part and being, at its upper part, in communication with the exhaust port of the engine through the medium of a passage provided in the wall of the said clutch housing and which passage registers, at its upper end, with an opening furnished in the bottom of the said casing and in register with the exhaust port of the engine.

The internal combustion engine employed is preferably a'water-cooled engine and, according to a further feature of the invention, a pump is provided in the lower part of said casing for circulating the cooling water through the engine cylinder, the suction side of said pump being connected by conduit means to a water straining unit provided at thelower end of the said drivingshaft housing.

According to further features of the invention the motor unit is carried by an attachment member so as to be capable of being turned from a and preferably the or each tiller bar is mounted when the said unit is in the rearwardly-propelling or astern position.

Further features of the invention will become apparent from the following description and the appended claims.

In order that the invention may be more readily understood one embodiment of the same, and a modification of such embodiment, will now be described by Way of example with reference to the accompanying drawings in which:

Figure l is a perspective view of an outboard motor unit constructed in accordance with this invention and suitable for use on a dinghy or the like;

Figure 2 is a perspective view, drawn to a larger scale than Figure l, of the upper portion of the outboard motor unit, the casing at the upper end of the unit being shown open;

Figure 3 is a vertical section through the upper part of the outboard motor unit shown in Figure 1, the section being taken on the axis of the driving shaft of the unit and the latter being shown, in this figure, in a rearwardly propelling position;

Figure 4 is a similar section to Figure 3 but of the lower part of the outboard motor unit;

Figure 5 is an elevation, drawn to the same scale as Figure 3, of the part of the unit shown in Figure 4 and as viewed in the direction of the arrow A in the latter figure;

Figure 6 is an enlarged section on line VI-VI, Figure l;

Figure 7 is a fragmentary section on line VII-VII, Figure 6;

Figure 8 is an enlarged vertical sectional view of some of the mechanism shown in Figures 6 and '7;

Figure 9 is a part sectional plan on line Di-JX, Figure 8;

Figure 10 is a side elevation showing the motor unit illustrated in Figures 1 to 9 ready for attachment to the transom of a dinghy and in a forwardly propelling position with its propeller rearwardly directed, the unit being in an operative position;

Figure 11 is a view similar to Figure 10 with the outboard motor unit turned through 180 (as compared with its position in the latter figure) about the axis of its driving-shaft housing so as to bring it into a rearward propelling or astern position with its propeller forwardly directed;

Figure 12 shows the outboard motor unit of Figure 10 raised into an up-tilted position in which its propeller will be clear of the beach or the like when the dinghy is being beached;

Figure 13 is a side elevation of the upper part of the outboard motor unit shown in Figure l of the drawings, the view being taken from the opposite side of the unit to that shown in Figure 1;

Figure 14 is a fragmentary side elevation showing a detail of the bearing sleeve for the driving-shaft housing and the means for locking said housing to the attachment member of the unit when the propeller of the latter is in the rearwardly propelling position;

Figure 15 is a view similar to Figure 14, partly in section, showing the driving-shaft housing turned to the rearwardly propelling position and locked against rearward movement relatively to the said attachment member;

Figure 16 is a perspective view of a detail of the mechanism shown in Figures 14 and 15; and

Figure 17 shows in vertical section, similar to Figure 3, a modified arrangement of the starter pulley for the engine of the unit.

Referring to the drawings, particularly Figures 3 and 4, it will be seen that the outboard motor unit there depicted comprises an internal combustion engine I adapted to drive a remotely situated screw propeller 2 through a driving shaft 3 extending between the engine and the propeller and enclosed in a hollow or tubular housing 4 having an attachment member 5 for attaching the outboard motor unit pendantly to the transom 6 (see Figures 10 to 12) of a dinghy or the like.

The engine and easing therefor The engine I, which is a single cylinder watercooled two-stroke internal combustion engine, is fixed on its side to the bottom I of the lower part 8 of a rigid hollow casing 9 in the form of a rectangular parallelepipedon, the upper part [0 of this casing forming a cover for the engine and being complementary to the lower part 8 of the casing so that when the said upper casing part is closed, as shown in Figure 11, for example it co-operates with the lowercasing part to enclose and protect the engine I.

As will be seen from the drawings the division between the upper and lower parts of the casing 9 extends horizontally of the casing rather nearer to the top than the bottom thereof, the two parts 8 and ID of the casing being hinged together at H, H along one side edge (see Figure 2) and being furnished along the other side edge with the fastening means, such as toggle fasteners l2, it.

In order to effect a water-tight seal between the two parts 8 and I0 of the casing 9 when the upper part It) is in its closed position, a sealing ring [3 is provided around the edge of one of these parts 8 and IE! and preferably around the upper edge of the lower part 8 as shown clearly in Figures 2 and 3, this sealing ring being of resilient character and conveniently formed of rubber or similar material and of circular or other suitable cross-sectional form, the ring being located in a recess in the upper edge of the lower casing part B so as normally to project somewhat above such upper edge when the upper casing part it) is raised.

The upper part 10 of the casing embodies therein a fuel tank H! for storing the liquid fuel for the engine I this tank being provided with a filling neck 15 closed by a detachable non-spill filler cap I 6 and a flexible pipe I! being provided for conveying liquid fuel from the bottom of a well l8 (provided in the base I9 of the fuel tank I 4) to the carburetor 20 connected to the inlet 28 (Figures 2, 3 and 13) of the engine I, such pipe permitting the upper part I!) of the casing 9 to be raised, and subsequently lowered, with respect to the lower part 8 of the casing 9 without interrupting the flow of fuel from the tank to the engine.

To limit the upward movement of the upper part I0 of the casing 9 with respect to the lower part 8 and to support the part ID in its raised position, a pivoted strut 2|, having an elongated bayonet-type slot, is provided on the casing part I0 for co-operation with a stud 22 on the lower casing part 8 as shown in Figure 2.

The fuel tank l4 embodied in the upper part 10 of the casing 9 is furnished on the inside thereof with recesses 23 and 24 respectively to receive the spark plug 25 and the flywheel and magneto assembly 26 of the engine and a starter cable pulley 2'! when the upper casing part I!) is in its closed position, the top of the upper part I 0 of the casing 9 being upwardly domed, as shown at 91, over the said fly-wheel and magneto assembly, all as will be clearly seen from Figures 2 and 3, for example.

The crank shaft 29 of the engine 1 is arranged so as to be perpendicular to the bottom 1 of the casing 9 and is journalled in the upper and lower ends of the crank case 3!] of the engine, this crank case having a dependent flange 3| around the lower end of which is an externally cylindrical rib 32 coaxial with the crank shaft 29 and fitting coaxially into a circular aperture 33 (Figure 3) in the bottom I of the lower casing part B so as accurately to position the engine I with respect to the casing part 9 and with its crank shaft 29 in end-on alignment with the driving shaft 3. The aperture 33 is located nearer to one end of the casing 9 than to the other end thereof and the engine is secured in position in the casing by means of screws and/or bolts (not shown).

C'Zntch assembly and housing therefor ing 25 are respectively marked 3'1 and 38, see

for example Figure 3. The inner wall 37 is cylindrical at its upper part and frusto-conical at its lower part, and is, as a whole, coaxial with the crank shaft 39. The outer wall 38 of the clutch housing is of a streamlined or approximately elliptical form in horizontal cross-section at its upper part but converges downwardly and inwardly at its lower part to meet and match an upwardly and outwardly flared part til at the upper end of the driving-shaft housing t which is bolted to the lower end of the clutch housing 35.

' The upper part of the outer wall 38 of the clutch housing is rearwardly ofiset with respect to its inner wall 3! as is clearly seen from Figures 3, 6 and 'l, so as to provide respectivel at the front and rear of the clutch housing between the outer and inner walls thereof two passages marked 4? and M and both extending downwardly completely through the wall of the clutch housing, the passage 50 serving to house a water pipe 42 and to discharge engine cooling water all as subsequently referred to in more detail, whilst the passage fil serves to conduct exhaust gases from the exhaust port 63 of the engine I to the upper end 39 of the driving-shaft housing 4 which, besides housing the driving shaft, also serves as an exhaust pipe and cooling water discharge conduit for the engine. The said driving-shaft housing gradually increases downwardly in' cross-sectional area at its lower part which is of a rearwardly streamlined horizontal cross-sectional form, such lower part of the housing being provided, at its lower rear extremity, with an exhaust opening 4% (see Figure 4) for the egress of the exhaust gases and cooling water flowing through the driving-shaft housing from the engine. Moreover, the said lower part of the driving-shaft housing is extended so far rearwardly, as shown in Figure 4, that the rearward extension will constitute a rudder 45 located above the exhaust opening 44, and also a cavitation plate.

In order that the inner wall of the clutch housing shall be accurately aligned with the aperture 33 in the bottom of the lower part 8 of the casing 9 and thus with the crank shaft 29 of the engine I, the upper end of the housing is furnished with an annular rib 36 there around and fitting into the lower end of the said aperture 33.

Engine water cooling system The lower end of the driving-shaft housing 4 carries a streamlined underwater unit comprising a water straining unit 48, a propeller unit 41 and a guard or tail fin 48, the propeller unit being sandwiched between the water straining unit and the guard fin 38 and these three parts being secured together by bolts d8 passing therethrough. The water straining unit is includes a water chamber 5% the wall of which is provided with a series of perforationsbl to admit strained water to the chamber 59 which is located in the front of the water straining unit (as is clear from Figures 1 and 4) so that this water can be drawn into the chamber by a water pump 5% (see Figure 3) which draws the water upwardly through a non-return valve 52 (dipping into the water chamber 50) and into and up the pipe 42, previously referred to, the upper end of this pipe being in communication with the water inlet 53 of the water pump 54 which is fixed to the front end of the crank case 39 of the engine I within the lower casing part 8.

The pump 55 is of the diaphragm type and its diaphragm 55 is arranged opposite an aperture 5B in the said end wall of the engine crank case 351 so as to be responsive to the cyclical variations in the internal pressure of the said crank case whereby the diaphragm is vibrated and water is pumped up the pipe 42 through the pump inlet 53 as stated and then circulated through an outlet 51 and a pipe 58 (see Figure 2) to the head of the cylinder of the engine l and then into awater jacket 59 of this cylinder for cooling purposes, the water leaving the said water jacket '59 (after circulating therethrough) via an outlet passage $39 (see Figure 3) leading to a vertical discharge passage in a bulge on the rear end of the clutch housing 35 and discharging into a horizontal outlet chute 52 and/or into a by-pass 63 (see Figures 6v and '7).

The by-pass E3 is formed in the upper surface of the wall of the clutch housing 35 and com-' municates with the exhaust passage 'll through this wall, as clearly shown in Figure 6, and a slide valve G l is provided in the passage ti so that the water discharge via the chute 62 can be almost entirely out off, the arrangement preferably being such that this valve 6 3' will, when the engine I is operating, be so set that only a mere trickle of water leaves the chute 52 as an water jacket 59, whilst the majority f the Water.

is discharged through the exhaust port M, down the driving-shaft housing 4 and out of the latter via the exhaust opening 44. The valve 64 also constitutes a pressure releasing cock and will be fully opened when starting the engine to relieve the back pressure on the exhaust gases and thereby to facilitate starting the engine.

The cooling water discharged through the driving-shaft housing 4 serves to counteract the heating effects of the exhaust gases passing through the housing.

The diaphragm 55 of the pump 54 is preferably subjected to slight spring pressure by means of a compression spring 65 arranged on the pump side thereof and the inlet 53 and outlet 51 of the pump are controlled by non-return valves respectively marked 66 and 61 (Figure 3) which ensure a unidirectional flow of the cooling water through the engine.

Driving shaft To Protect the driving shaft 3 from the effects of the exhaust gases and cooling water flowing through the driving-shaft housing 4, and from any other water that may enter such housing, the driving shaft is enclosed by means of an enshrouding tube 88 coaxial with the driving shaft and fitted Water-tightly at its upper end upon a coaxial dependent boss 69 on the lower end of the clutch housing 35 (see Figure 3) whilst the lower end of the tube 68 is fitted over an upstanding frusto-conical boss 10 formed integrally upon the upper end of the water straining unit 46, the lower end of the tube 68 being clamped on to this boss by means of a ferrule ll having a frustoconical bore to match the external form of the boss 76, the ferrule i! being drawn down the boss 78 by means of set screws 12 (see Figure 4). Thus the driving shaft 3 is completely segregated from the interior of the driving-shaft housing throughout its whole length and the upper end of the water straining unit is also segregated from such housing so that water and exhaust gases may not pass to the propeller unit.

The assembly of the water straining unit, propeller unit and the guard fin are secured to the lower end of the driving-shaft housing 4 by studs '13, the said unit being centralised with respect to the driving shaft 3 by means of a central short spigot 7:. on the upper end of the water straining unit and fitting into a hole 15 in the lower end of the driving-shaft housing, this hole being coaxial The propeller unit includes a gear box 16 in which is vertically arranged a worm shaft 1'! carried in anti-friction bearings 78 and 19 respectively located at the upper and lower ends of the gear box, the shaft ll being coaxial with the driving shaft 3 and carrying a worm 80 meshing with a worm wheel 8| (see Figures 4 and 5) fixed upon a propeller shaft 32 which is arranged at right angles to the shaft H but laterally offset with respect thereto as is clearly seen from Figure 5. The propeller shaft is housed in a streamlined hollow housing or bulge 83 formed on the side of the propeller unit gear box 16 and the propeller shaft is suitably journalled in this bulge in Oilite or other suitable bearings, the bulge being furnished with .a water-tight gland or seal 84 at its rear end and with a thrust ball 85 at its front end, this ball being located in a recess in the front end of the propeller shaft and hearing against a hardened disc 86 let into the inner side of a removable cap 81 at the front end of the said bulge.

The upper end of the worm shaft TI is drivingly and detachably coupled to the lower end of the driving shaft 3 which, in this case, is in the form of a tube, the upper end of the driving shaft being received and journailed in the dependent boss 69 of the clutch housing 35, and being detachably coupled to the lower end of a coaxial transmission shaft 88 journalled in an anti-friction thrust bearing 89 in the lower end of the clutch housing 35 and restrained against axial movement in this housing.

The transmission shaft 88 is coaxial with the crank shaft 29 of the engine I and, as will be seen from Figures 3, 6, '1, 8 and 9 in particular, forms part of the clutch assembly of the outboard motor unit and although the transmission shaft is preferably made separately of the driving shaft 3 it could be, if desired, an extension of this shaft.

At is upper end the transmission shaft 88 has an inset hardened steel disc 96 on which bears a thrust ball 9! let into the lower end of the crank shaft 29 of the engine i, this arrangement relieving the end thrust on the crank case bearings for the engine crank shaft, the end thrust of the crank shaft being transmitted through the said ball 9| and transmission shaft 88 to the bearing 89 for the latter.

Details of the clutch assembly The clutch is of the expanding friction shoe type and comprises a male and a female part, the female part consisting of a drum 92 fixed coaxially on the conical lower end of the crank shaft 29 and receiving therein a pair of arcuate friction shoes 93 and 54 (see Figures 3, 6, '7, 8 and 9) carried upon the male part of the clutch which consists of a disc 95 keyed :upon the transmission shaft 88 coaxially therewith and at a short distance from its upper extremity.

The friction shoes 93 and 94 are each of partcircular form in plan and each has one end pivotally associated with the plate 95 inwardly of the periphery of the latter, the opposite ends of the shoes co-operating with an expanding cam 108 the operation of which is subsequently described.

The pivoting of the friction shoes 93 and 34 to the plate 95 is effected in an adjustable manner by providing the plate 95 with a fixed tubular pillar 96 projecting perpendicularly upwardly therefrom, this pillar having a pair of diametrically arranged radial bores in which are respectively mounted bearing balls 98 and 99 seatingin recesses Hi8 and Ill! respectively provided in the pivoted ends of the friction shoes, the portions of the said balls 98 and 99 located within the tubular pillar 96 bearing upon an adjusting ball I62 which can be moved upwardly axially of the tubular pillar 96 by means of an adjusting screw I03 (see Figure 7) screwed into the plate 95 and bearing, at its upper end upon the ball I02, such adjusting screw I03 being provided with a lock nut I04. The ends of the friction shoes .92 and 94 which engage the expanding cam I53 are maintained in contact with this cam by means of a low rate tension spring connected at opposite ends to lugs [06 and ID! respectively provided on the said shoes.

The cam l 08 is mounted on a pivot I09 projecting perpendicularly upwardly from the clutch plate and is furnished with a substantially radial arm H6 extending to the centre of the clutch late 95 and suitably joggled so as to be 1. 9 located at its free end adjacent the external periphery of that part of the transmission shaft 88 which projects above the clutch plate 95, this free end of the lever I I9 having an oblique thrust surface II I (see Figure'8) with which engages a ball H2 located partially in an axial bore H3 in the transmission shaft 83 and partially in a radial bore H4 leading outwardly from said axial bore, the ball H2 being adapted to be thrust radially outwardly with respect to the transmission shaft 88 (thereby to operate the cam lever HQ and expand the friction shoes 93 and 9d into contact with the dependent flange of the drum 52) by means of an axially slidable clutch adjusting or push rod 1 I 5 mounted in the axial bore I I3 of the transmission shaft 88 and adapted to be slidden endwise in the latterthrough the medium of a peripherally grooved collar or bobbin I It mounted on the exterior of the transmission shaft 88 so as to be slidable axially therealong, such collar being coupled to said clutch adjusting rod H5 by a diametrical cross pin I I! carried by said rod and engaging in diametrically opposite holes in the said collar, the transmission shaft 88 being longitudinally slotted at H8 to provide for the necessary movement of the cross pin I IT.

The collar H6 is slidden along the transmission shaft 88 through the medium of radial pins and rollers I26 on the free ends of a semi-circular forked lever H9 (Figures 6, 7, and 8) carried upon a horizontal shaft I journalled in the lower part of the clutch housing 35 and extending to the exterior of the latter where it is provided at one end with an operating handle IZI, the arrangement being such that, when the loandle I2I is raised from the lower position shown in dot and dash lines at I22 (Figure 8) to the upper position shown in dot and dash lines at I23 in the same figure, the push rod H5 will be raised so as to cause an oblique surface I24 provided at its upper end to push the ball H2 radially outwardly thereby to expand the friction shoes 93 and 94 of the clutch and bring the two parts 95 and-92 of the clutch into driving engagement.

Any suitable means may be provided for releasably retaining the operating lever IZI for the clutch adjusting rod in its terminal positions and, in the embodiment of the invention illustrated, the lever remains in its disengaged or lower position by virtue of its weight and of the engagement of the diametrical cross pin I I! against the bottom of the slot H3 inthe transmission shaft 88 whilst the lever I2I isternporarily locked in its upper position by the snap engagement of the ball H2 in a notch I25 in the adjusting rod H5.

Attachment member for the unit The outboard motor unit is adapted to be mounted on the transom 6 of the dinghy by means of an attachment member 5 comprising a substantially upright body I21 having, at its upper end a forwardly extending inverted U- shaped clamp (see Figures 1, 3, 10 to 12, 14 and 15) adapted to engage over the upper edge of the transom centrally of the width of the latter, the clamp comprising a pair of forwardly and downwardly extending arms I228 each of which carries, at its lower end, a clamping screw I29 adapted to engage on the inside of the transom to clamp the latter between their rear ends and the front surface of the body I2! of the attachment member. Y

The upper part of the attachment member 5 is (if desired, with the aid of a rubber bush) pivoted on a horizontal bolt I30 passing through the upper end of an upwardly and forwardly directed bracket I3! united at its lower part'to the front portion of an internally cylindrical bear'mg sleeve I32 in which is journalled a cylindrical port I33 (see Figures 3, 14 and 15 for example) of the driving-shaft housing i, the upper and lower ends of the said sleeve being located between circumferential shoulders EM and I35 at the ends of the said cylindrical part of the driving-shaft housing so as to be restrained by these shoulders against endwise movement with respect to such housing.

The sleeve I32 is made in two similar semicylindrical halves bolted together about the driving-shaft housing and the latter is freely rotatable about its own axis in the bearing sleeve so that the propeller 2 of the outboard motor unit can be moved from a forwardly-propelling rearwardly-directed position, such as shown in Figures 1 and 10 for example, to a forwardly-d1;- rected rearwardly-propelling reverse or astern position, such as is shown in Figures 4 andll for example, or into any position intermediate these two alternative positions.

It should also be understood that the complete motor unit, other than the attachment member, is capable of being swung in a vertical plane about the horizontal pivot bolt Hit so that the outboard motor unit can be swung from a more or less upright operative position in which the propeller is below water level (shown for example in Figures 10 and 11) to a position such as that shown in Figure 12 where the unit is raised into an up-tilted position (at about 45 to the horizontal) with the propeller lifted above beach level and probably out of water so as to avoid damage to the outboard motor unit during, for example, the beaching of the dinghy to which it is fitted.

At its lower end the body it! of the attachment member 5 is provided with a pair of laterally spaced parallel rearwardly extending arcuate horns I 36 each having a longitudinal slot I36 whose centre of curvature lies on the axis of the pivot bolt IN. The horns I36 embrace between them the said driving-shaft housing l and are respectively secured, by locking screws it? passing adjustably through the said slots I36, to the opposite ends of a substantially semi-cylindrical or segmental bridge piece I38 (see Figures 1, 3, 14 to 16) lying around the lower front part of the cylindrical portion I33 of the driving-shaft housing}, the front part of the bearing sleeve I32 being shorter than the rear part of this sleeve in order to accommodate the bridge piece I38 therebelow with this bridge piece forming, as it were, a separate but complementary portion of the sleeve I32. Thus the bridge piece I38 serves to bear the forward thrust of the driving-shaft housing when the propeller of the unit is in its rearwardly-directed forwardly-propelling position, such as shown in Figures 1 or 10 for example, but does not interfere with the free rais ing of the outboard motor unit into an up-tilted position such as that shown in Figure 12 so long as the propeller 2 is in the rearwardly-directed forwardly-propelling position. 1

However, in order to loci: the outboard-motor unit in a more or less upright operative position, such for example, as that shown in Figure 11, when the propeller is the forwardly-directed rearwardly-propelling position, the bridge piece I38 and the driving-shaft housing are provided with means for"i.nterlocl:ingly engaging with one another when they outboard motor unit is turned to its said rearwardly propelling position, such interlocking means comprising, in the embodiment illustrated, a part cylindrical or segmental upstanding locking flange I39 formed in-- tegrally on the rear part of the driving-shaft housing adjacent the lower shoulder I55 thereof, this locking flange being adapted, when the outboard motor unit is turned from a forwardly propelling to a reverse position, to enter and interlockingly engage in a semi-annular openended groove I40 in a peripheral bulge MI provided around the lower part of the bridge piece I38, see Figure 15 for example.

The locking flange I39 is coaxial with the driving shaft 3 and the cylindrical part I33 of the driving-shaft housing 4 and also partially surrounds the bearing sleeve I32 at the lower end thereof and it will be seen that, when the flange I 39 is engaged in the groove I 40, the drivingshaft housing is interlocked'rigidly to the attachment member 5 so as to prevent the outboard motor swinging rearwardly when the unit is being used in the astern or reverse position.

Preferably the bearing sleeve I32 is provided with semi-cylindrical bearing liners I42 and M3 for the driving-shaft housing, these bearing liners being arranged respectively in the rear and front halves of the sleeve; a similar bearing liner !44 is also preferably provided in the bridge piece I33.

It will be appreciated that by the provision of locking screws I3? operating in the arcuate slots I30 in the horns I35, the actual angular setting or operative position of the outboard motor unit with respect to the transom of the dinghy can be adjusted between a strictly vertical position and a somewhat oblique position.

When the outboard motor is not in use and it is, for example, to be stored, the attachment member 5 may be swivelled about the drivingshaft housing so as to be situated below the rear end portion of the engine casing 9, as shown in Figure 3 for example, the arrangement being such that when so disposed the attachment member is wholly located within the overall dimensions of the said casing so that the unit is in a compact condition for storage or transport.

Means for supporting unit in an up-tilted position In order to support the outboard motor in its raised or uptilted position, such as shown for example in Figure 12, while pulling the dinghy up or down a beach or in similar circumstances where it is necessary to protect the propeller from damage, the forwardly and upwardly directed bracket I 3| and the attachment member 5 are respectively furnished with a pivoted loop I45 and a lug I46, the loop being adapted to be engaged over the said lug when the driving-shaft housing 4 occupies its raised or uptilted position so as thereby releasably to retain the outboard motor unit in this position. In the embodiment of the invention shown, the loop I45, is, as will be clearly seen from Figures 1, 3 and to 11, for example, pivoted at its upper end to a forward extension I41 of the bracket I (H whilst the lug I46 which has an undercut or hooked nose portion I48 forms an integral part of the attachment member 5, being disposed centrally between the forward dependent portions of the arms 28 of such member. In the arrangement shown the loop I45 serves to retain the outboard motor unit with the axis of the driving shaft 3 at about 45 to the vertical.

Carrying handle To facilitate the carrying of the outboard motor unit with. the driving-shaft housing 4 in a more or less horizontal position, the sleeve I32 is provided, on its rear part, with an integral handle I49.

Tiller bar arrangement For steering and manipulating the outboard motor unit, one or more tiller bars are provided and such tiller bar or each of them is of a stowable or retractible character. In the embodiment of the invention shown in the drawings two such tiller bars are provided, and are marked respectively I and I5I, these two tiller bars being intended for alternative use, the tiller bar I5I being used (as shown in Figure 10) when the outboard motor unit is in the forward-propelling or ahead position and the tiller bar I50 being used (as shown in Figure 11) when the outboard motor unit is in the rearwardly-propelling or astcrn position.

The tiller bars I50 and I5I are arranged in parallelism one above the other in the lower part 0 of the casing 9, the tiller bars being parallel to the bottom I of this casing and both the bars being capable of being telescoped substantially wholly into and housed or stowed within the casing 9 and one of the bars, namely, the bar I5I, being withdrawable into a forwardly extended position beyond the front of the casing 9, as shown in Figure 10, whilst the other bar I 50 is extensible beyond the rear end of the casing (turned to the front when this tiller bar is extended) as shown in Figure 11.

Each of the tiller bars I50 and I5I is in the form of a metal tube supported in a pair of axially spaced guides, one of these guides being constituted by an end wall of the lower part 8 of the casing 9 and the other guide being formed by a lug I52 formed integrally with the lower part 8 of the casing 52 and on the interior of this casing part as is clearly seen, for example, from Figures 2 and 13.

The tiller bars I50 and I5I respectively pass through holes in the rear and front ends of the casing 9 and are sealed in these holes by resilient bushes or glands I53 (made of rubber or a composition of rubber or a synthetic resin such as polyvinyl chloride or alkathene or other suitable material) which also serve frictionally to retain the tiller bars in any axially adjusted positions in which they may be placed.

The tiller bars also pass through holes in the lug I52 and these holes are fitted with resilient bushes I54 similar to the bushes I53, and although these bushes I54 are not required to effect any sealing they do assist in retaining the tiller bars in their axially adjusted positions. Each tiller bar is provided at its opposite ends respectively with a head I55 and a collar I56 to limit the endwise movement of the bar.

carburettor housing The carburettor 20 of the engine is to one side of the cylinder of the latter and depends through an opening I51 (see Figure 13) in the bottom of the lower part 8 of the casing 9 and is surrounded by a dependent cowl I58 formed integrally with the bottom I of the casing 9 and furnished, at its lower end, with an air inlet opening I59 covered by a gauze I60 to prevent water spray entering the casing and the carburettor whilst permitting air to enter the latter. A choke having a control knob IE2 is provided for the carburettor, and also a needle valve ISI for adjusting the jet of the carburettor, these controls passing through the cowling I58.

Throttle and magneto controls The throttle control for the carburettor comprises a push rod I63, the inner end of which is connected to a lever on the carburettor butterfly valve spindle (not shown in the drawings as it is of normal form), the push rod I63 being located mainly inside the lower part 8 of the casing S and projecting outwardly through a hole formed in the front end of the latter and furnished with a resilient sealing bush H54 similar to the bushes or glands E53 previously described, the rod I53'having an operating knob 65 at its outer end. A similar push rod I55 (Figures 2 and 13) is also mounted in the front end of the lower part 8 of the casing 9 in a-resilient sealing bush It? and serves to adjust the advance and retard setting of the magneto, the rod being connected to an angularly adjustable plate I68 at the base of the magneto-flywheel assembly 25 and which carries the terminal (not shown) to which is connected a lead I69 to the sparking plug 25.

The throttle and magneto controls are preferably arranged, as shown, at the front end of the casing 9 adjacent the tiller bar Ii which is the one most frequently used as it is employed during forward movement of the dinghy. It will, however, be appreciated that these controls may be duplicated at both ends of the casing if desired. a

Inspection covers Modification of starter pulley arrangement In the embodiment of the invention described in Figures 1 to 16 of the drawings it is necessary to open the casing 53 by raising the upper part I!) thereof in order to apply the starter cable to the starter cable pulley 2'5, but if desired the unit may be modified so that the starter cable can be operated from the exterior of the casing 9 without raising the upper part II) thereof. Thus, as will be seen from the modification illustrated in Figure 1'? of the drawings, the starter pulley 2'! of the arrangement shown in Figures 1 to 16 may be replaced by a starter pulley 2'? independent of the engine crank shaft is and freely rotatable upon a vertical pivot pin 5'13 fixed centrally in a central boss I'M on the dome 81 of the'upper part iii of the casing e, the said pulley being urged in one rotational direction by means of a spiral or clock type rewinding spring I75 fixed at one end to the pulley and at its other end to a surrounding dependent flange IIii formed integrally-with, and onthe under side of, the dome Pi? coaxially with the pivot pin H3.

one end portion of a starter cable ii"! is fixed to the external periphery of, and is wrapped around, the pulley 2i whilst th other end portion of the cable passes out through an opening in the front end of the casing 9 and is furnished with an operating knob lift, a sealing gland (not shown) being arranged around the cable where it leaves the casing 8, if desired. I To couple the puliey 2? to the crank shaft 29 and to transmit rotation from the pulley to the crank shaft when the pulley is rapidly rotated by the cable I", the pulley is provided withan eccentric vertical pivot pin I19 upon which is pivoted one end of a pawl or dog I80, the other end of which is urged inwards (towards the centre of the pulley) by means of a low rate tension spring I8I anchored at one end to the pawl or dog and at the other end to a coaxial dependent extension I 82 or" the pivot pin I133.

The pawl or dog 58!] is adapted for co-operation with internal ratchet teeth I83 of an annular ratchet I84 rigidly mounted on the fly-wheel cover I85 of the magneto and fly-wheel assembly 26 coaxially with the crank shaft 29 of the engine, and the arrangement is such that the pawl or dog t8!) does not normally engage the ratchet teeth I83 but only does so when the starter pulley 27 is rapidly rotated by pulling out the cable I21, centrifugal force then causing the free end of the dog or pawl to fly outwardly and engage in the said ratchet teeth, whereafter the flywheel and crank shaft are rotated unitarily with the starter pulley until the engine starts, the ratchet teeth then over-run the dog or pawl. On being released the cable Ill is automatically rewound on to the cable pulley 2? by the action of the spiral spring H5 which, although initially tensioned, is further tensioned by the withdrawal of the starter cable to start the engine. Thus it will be clear that the engine can be started without opening the casing 9 and that the only time it will be necessary to open this casing will be when it is required to inspect the engine or, for example, to flood the carburettor before starting the engine. After the engine has once been started, should it then stall, it will usually be possible to restart it without opening the casing 9 and merely by operating the starter cable I'I'I. It will be noted that when the upper part ID of the casing is raised, the starter pulley is lifted with it.

Conveniently the casing 9, clutch housing 35, driving-shait housing 4, water strainer unit 415, propeller unit 41, fin 45, bearing sleeve I32, attachment member 5, and bridge piece I38 are all formed as castings of a light-weight alloy such as, for example, an aluminium alloy. A unit so constructed and employing a 1%; H, P. engine and of overall dimensions of 12 X 9% x 3-2" will weigh approximately only 33 lbs.

Some advantages of the outboard motor units above described By entirely enclosing the engine in a rigid casing as above described the engine is protected from water spray, rain, and the atmosphere and consequently gives improved service as compared with less protected engines. In addition, when the casing 9 is closed, noise from the engine is in the past do not seriously hinder the transmission of sound from the engine and in many cases add to the noise rather than detract from it. In addition the total enclosing of the engine in a rigid and robust casing protects the engine and parts connected therewith from mechanical clamage which is an important advantage since outboard motors are liable to receive somewhat rough handling. Also by providing the unit with a worm gear propeller drive'it is possible-to run the propeller at a speed much less than that of the engine crank shaft, whilst providing a higher power output than usual and permitting, if desired, the use of a larger propeller (e. g. a 9% diameter x 15'' pitch weedless propeller) than can normally be used.

The construction of the outboard motor unit in accordance with this invention also enables a water-cooled engine to be used instead of an air cooled engine and this is a further advantage because, as is well recognised, a water cooled engine is quieter in operation than an air-cooled engine. Moreover, the provision in the unit of a clutch assembly enables the engine to idle whilst the propeller is stationary and permits the propeller to be brought into or taken out of operation instantly when required, this facilitating the manoeuvring of the dinghy to which the outboard motor unit is applied. Furthermore by embodying the fuel tank in the easing as above described, the unit is rendered selfcontaincd and compact and the fuel tank can be made of a rigid and robust construction unlikely to sustain material damage in ordinary use.

Finally, by arranging for the tiller bars to be stowable within the casing 9 as above described and for the attachment member to be capable of being stowed below the casing 9 within the overall dimensions of the outboard motor unit, transport and storage of this unit is greatly facilitated.

I claim:

1. An outboard motor unit for boats, such unit comprising a hollow rigid casing formed in two complementary parts hinged together so that one of such parts may be opened relatively to the other part to give access to the latter part; fastening means for securing the said openable casing part in its closed position; a single cylinder two stroke water cooled internal combustion engine fixed on its side in the bottom of the said other casing part with its crank shaft arranged transversely of said bottom and aligned with a hole in the latter; a tank for the fuel for the said engine and formed integrally with the said openable casing part; a flexible pipe for supplying fuel from said tank to the said engine and permitting said openable casing part to be moved relatively to the other casing part without interrupting the how of fuel to said engine; a clutch assembly connected to the lower end of the crank shaft of the said engine; a clutch housing for said clutch assembly and rigidly secured to the underside of the said other casing part and depending therefrom; a driving shaft depending downwardly from the said clutch assembly and connected at its upper end to the latter; a tubular combined driving-shaft housing and coolingwater and exhaust gas discharge pipe, such housing being fixed at its upper end to, and depending from, the lower end of the said clutch hous ing to which it is rigidly secured; a propeller unit fixed to the lower end of the said drivingshaft housing; a propeller shaft journalled in said propeller unit at right angles to said driving shaft; transmission gearing between said driving shaft and propeller shaft; a propeller fixed on said propeller shaft; a water pump in said other casing part, said pump being driven by said engine and having its outlet connected to water cooling system of the latter; conduit means leading from the lower part of said driving-shaft housing to the inlet of said pump; controls for-said engine and said clutch assembly arranged externally of the said casing and clutch housing respectively; an attachment member adapted to be secured to the stern of a boat; a bearing sleeve in which the upper midportion of the said driving-shaft housing is coaxially journalled so as to be rotatable about the axis of the said driving shaft relatively to said sleeve, such bearing sleeve having its upper part connected to said attachment member for tilting movement about an axis forwardly offset from, and at right angles to, the said driving shaft; means for adjusting the angular relation between the said driving-shaft housing and said attachment member; means for locking the said bearing sleeve against tilting relatively to the said attachment means when the said propeller is in the astern position; and stowable tiller means for rotating the said casing and parts fixed thereto about the axis of the said driving shaft and relatively to the said attachment member.

2. An outboard motor unit for boats, such unit comprising a water-cooled internal combustion engine disposed with its crank shaft substantially vertical; a screw propeller remotely situated with respect to said engine; a driving shaft extending between said engine and said propeller; a hollow rigid casing including complementary upper and lower parts, said engine being rigidly secured in said lower casing part and said upper casing part being hinged to said lower casing part so that, when closed, it co-operates with said lower casing part to form a cover for, and enclose and protect, said engine; sealing means disposed between said upper and lower casing parts water-tightly to seal the same together; means for maintaining said upper casing part closed; a fuel tank rigidly carried by, and internally of, said upper casing part and adapted, when said upper casing part is closed, to lie above said engine; a flexible conduit extending between said fuel tank and said engine for conveying fuel to said engine and permitting the said upper casing part to be opened without interrupting the fuel supply to said engine; a tubular housing enclosing said driving shaft and rigidly connected to said lower casing part; a cooling water inlet port at the lower part of said housing; a cooling water circulating pump adapted to draw water in through said cooling water inlet port and to pass the same to the said engine to cool the latter; a bearing sleeve surrounding a portion of said tubular housing and in which the latter is, between its ends, rotatably journailed; and means for attaching said bearing sleeve, and thereby the whole unit, to the stern or transom of a boat.

3. An outboard motor unit according to claim 2, wherein there is provided, for facilitating the steering and manipulation of the said unit, at least one tiller bar telescopically slidable in said casing in a direction transverse to the axis of rotation of the unit and sealing means around said tiller bar to seal said casing.

4. An outboard motor unit according to claim 2, including a starter pulley freely mounted for rotation on the inside of said upper casing part; an internally toothed annular ratchet coaxially fixed to the engine crank shaft, said starter pulley and said ratchet being coaxial when the casing is closed; a spring retained pawl carried by said starter pulley and adapted, when the latter is rapidly rotated, to be urged by centrifugal force against the action of the spring into engagement with said ratchet thereby to couple together said starter pulley and said crank shaft; a flexible starter cable attached to said pulley so that by pulling on the cable said starter pulley may be rapidly rotated; and a re-winding spring to re-wind said cable on to said starter pulley when the former is released.

5. An outboard motor unit according to claim 2, including a forwardly directed bracket on the said bearing sleeve and by which the latter is tiltably connected to the said attachment member, and a pivotal loop and a lug respectively provided on the said bracket and the said attachment member, such lug and loop being adapted for interengagement to support the said driving-shaft housing in an up-tilted position with respect to the said attachment member when desired.

6. An outboard motor unit according to claim 2, wherein the said pump is a diaphragm pump whose diaphragm is exposed to, and operated by, the cyclical variations of the pressure in the crank case of the said engine.

'7. An outboard motor unit according to claim 6, including a manually operable back-pressure release valve for use when starting the engine of the unit and affording, at the upper end of the unit, an alternative discharge outlet for the en'- gine exhaust gases and cooling water.

8. An outboard motor unit according to claim 7, including a propeller unit carried at the lower end of the said driving-shaft housing, such propeller unit comprising a housing, a propeller shaft journalled in this housing and extending transversely of the axis of the said driving shaft, such propeller shaft rigidly carrying a toothed gear meshing with another toothed gear driven by the said driving shaft; and a central thrust ball located between the front end of the said propeller shaft and the front end of the housing containing such shaft.

9. An outboard motor unit according to claim 2, including a clutch housing disposed between, and rigidly associated with, the bottom of said casing and the upper end of said driving shaft housing; a clutch assembly located in said clutch housing between said crank shaft and said driving shaft, said clutch assembly comprising a transmission shaft and two co-operating clutch parts, one fixed coaxially upon the lower end of the crank shaft of said engine and the other upon the transmission shaft which is coaxial with, and disposed between, said crank shaft and the said driving shaft and is fixed to the latter, and means for actuating the clutch from manually controlled operating means arranged externally of the clutch housing.

10. An outboard motor unit according to claim 9, wherein the said clutch assembly includes a male clutch part fixed to said transmission shaft and a female clutch part, in the form of a drum, fixed coaxially to said crank shaft; expansible friction shoes carried by said male clutch part; friction shoe expanding means operable from the exterior of said clutch housing for expanding the said friction shoes into contact with said drum, and spring means for disengaging said shoes from said drum when the shoes are relieved of the action of said expanding means.

11. An outboard motor unit according to claim 10, wherein the said friction shoe expanding means includes a push rod slidable endwise in an axial bore in the said transmission shaft; means, operable from the exterior of said clutch housing, for moving said push rod in said endwise direction relatively to the said transmission shaft, a thrust element located in a lateral opening provided in said transmission shaft and leading to the bore of the latter, said thrust member being engaged with an oblique thrust surface on said push rod so as to be pushed radially outwardly with respect to said transmission shaft when the said push rod is moved in one endwise direction in said transmission shaft; an expanding cam for expanding said brake shoes; and a lever fixed at one end to the said cam and operable at the other end by said thrust member for expanding said friction shoes.

12. An outboard motor unit according to claim 11, wherein a thrust ball is arranged between the upper end of the said transmission shaft and the lower end of the engine crank shaft.

13. An outboard motor unit according to claim 12, wherein the said driving-shaft housing constitutes an exhaust pipe for the engine, the housmg being in communication at its upper end with the exhaust port of the engine and having an exhaust opening at its lower end, an enshrouding tube being arranged around the said driving shaft within the housing for the latter and being sealed at its upper and lower ends respectively to the lower end of said clutch housing and in the lower end of said housing thereby to protect the said driving shaft from water and exhaust gases in the said housing.

References Cited in the file of this patent UNITED STATES PATENTS Number Name Date 1,941,360 Mathias Dec. 26, 1933 2,091,247 Williams Aug. 24, 1937 2,204,750 Conover June 18, 1940 2,224,900 Conover Dec. 17, 1940 2,256,831 Karey Sept. 23, 1941 2,346,148 Bosma Apr. 11, 1944 2,460,419 Kincannon Feb. 1, 1949 2,549,483 Kiekhaefer Apr. 17, 1951 2,549,484 Kiekhaefer Apr. 17, 1951 2,585,774 Robertson Feb. 12, 1952 FOREIGN PATENTS Number Country Date 985,118 France Mar. 7, 1951 

